<template>
  <!-- :style="{ width: width, height: height }" -->
  <div :style="{width:width,height:height}" :id="chartId"></div>
</template>

<script>
// 引入 echarts 核心模块，核心模块提供了 echarts 使用必须要的接口。
import * as echarts from "echarts/core";
// 引入柱状图图表，图表后缀都为 Chart
import { BarChart } from "echarts/charts";
// 引入提示框，标题，直角坐标系，数据集，内置数据转换器组件，组件后缀都为 Component
import {
  TitleComponent,
  TooltipComponent,
  GridComponent,
  DatasetComponent,
  TransformComponent
} from "echarts/components";
// 标签自动布局、全局过渡动画等特性
import { LabelLayout, UniversalTransition } from "echarts/features";
// 引入 Canvas 渲染器，注意引入 CanvasRenderer 或者 SVGRenderer 是必须的一步
import { CanvasRenderer } from "echarts/renderers";

// 注册必须的组件
echarts.use([
  TitleComponent,
  TooltipComponent,
  GridComponent,
  DatasetComponent,
  TransformComponent,
  BarChart,
  LabelLayout,
  UniversalTransition,
  CanvasRenderer
]);

export default {
  props: {
    chartId: {
      type: String,
      required: true
    },
    option: {
      type: Object,
      required: true
    },
    width: {
      type: String
    },
    height: {
      type: String
    }
  },
  data() {
    return {
      chartInstance: null
    };
  },
  mounted() {
    this.initChart();
  },
  // 组件销毁时echats
  beforeDestroy() {
    if (this.chartInstance) {
      this.chartInstance.dispose();
    }
  },
  methods: {
    // 初始化图表，设置配置项
    initChart() {
      this.chartInstance = echarts.init(document.getElementById(this.chartId));
      // 挂载
      this.chartInstance.setOption(this.option);
    },
    updateChart(newOption) {
      if (this.chartInstance) {
        this.chartInstance.setOption(newOption);
      }
    }
  },
  watch: {
    option(newV, oldV) {
      this.updateChart(newV);
    }
  }
};
</script>

<style>
</style>